Electronic structure of epitaxial SrRuO3 films studied by resonant photoemission

The electronic structure of epitaxial SrRuO3 thin films annealed at 300 °C in ultra high vacuum is studied by resonant photoemission spectroscopy using synchrotron radiation. The valence band photoemission spectra show a good agreement with theoretical band structure calculations indicating a good quality of the film surface. A method was proposed, which allows extracting the partial density of states in the case of weak and broad resonance. The Ru 4d spectral weights obtained experimentally are in a very good agreement with theoretical predictions, confirming a strong mixing between Ru 4d and O 2p states, as well as the signature of electron correlation near the Fermi level in SrRuO3.